It really depends on a number of factors, one of which is your understanding of the test and requirements of the band scores. If your English is suitable for the band score you are aiming for, you will only need to focus on exam skills to make sure you reach your potential. The skills will help you understand how to approach questions and what the examiner is looking for in your writing and speaking. Once you feel comfortable with all that, you will have a clear idea of how long you want to practice before your test. Whatever you decide, make sure you are frequently getting the band score you want in practice tests.
All the best
According to the University of Colorado investigation, "His academic publications are nearly all works of synthesis and reinterpretation, drawing upon studies by other scholars, not monographs describing new research based on primary sources." The investigation also noted that "he has decided to publish largely in alternative presses or journals, not in the university presses or mainstream peer-reviewed journals often favored by more conventional academics."  In addition to his academic writing, Churchill has written for several general readership magazines of political opinion.
Bin Laden provided leadership and financial support for the plot, and was involved in selecting participants.  Bin Laden initially selected Nawaf al-Hazmi and Khalid al-Mihdhar , both experienced jihadists who had fought in Bosnia . Hazmi and Mihdhar arrived in the United States in mid-January 2000. In spring 2000, Hazmi and Mihdhar took flying lessons in San Diego, California , but both spoke little English, performed poorly with flying lessons, and eventually served as secondary – or "muscle" – hijackers.